 
|
| Home | Contact | Membership | Members | Firms | ASPNG Congress | Publications | Technical Support | Education | Links |
|
PNG94 is the gazetted national datum for Papua New Guinea (National Gazette of 22 May 1996). PNG94 is realised by the coordinates of 14 zero order geodetic stations within Papua New Guinea (listed below) related to the International Terrestrial Reference Frame 1992 (ITRF92) at epoch 1994.0 (same as GDA94 in Australia). It is defined as follows: Reference Ellipsoid: GRS80 Map Projection: Papua New Guinea Map Grid 1994 (PNGMG94) Projection type: Universal Transverse Mercator (UTM) Usage: PNG94 should be used as the geodetic datum for all cadastral, topographical, engineering and resource sector surveys commenced after 2000. Access: Surveys should be connected to the nearest high order PNG94 control. This can be by means of connection to a PNG94 coordinated monument, or to a CORS station. Because of the highly complex tectonic setting in PNG, the closest coordinated monument should be used for connection. First Order Coordinate Listing: Click on the link PNG94 1st order adjustment 2008 (update 1st December 2011) to view and download the spreadsheet of the current first order coordinate list for PNG94. The adjustment has resulted in small changes in the original zero order PNG94 realisation (listed in the table below). The data area also provided as a Google Earth kml file Site and access information for these stations (and others) are available at the Australian National University Research School of Earth Sciences: PNG GPS Site Information Note that the coordinates in these site logs are ITRF2000 at epoch 2000.0 and may be up to 0.5 m different from the PNG94 values. Using PPP, AusPOS and OmniSTAR with PNG94: These GNSS precision surveying systems and post-processing services deliver coordinates in terms of ITRF2005 or ITRF2008 and these coordinates will be up to two metres different from PNG94. A block-shift correction to be applied to derived coordinates from these systems can be determined by occupation of the nearest PNG94 coordinated monument. Coordinate transformations: Since PNG94 and GDA94 share the same realisation, the GDA94 technical manual can be used with PNG94 (substitute PNG94 for GDA94 and PNGMG for MGA). The GDA94 technical manual is accessible at GDA94 Technical Manual Elevations: PNG Ellipsoid heights are up to 85 metres different from MSL and a suitable geoid model should be used for transformation of ellipsoidal heights to MSL. A provisional MSL aligned geoid model PNG08 for PNG has been developed using EGM2008 source data. Visit the vertical datum web-page to obtain more information and to download the PNG08 geoid files in different formats. The PNG94 geoid developed by Prof. W. Kearsley no longer can be used on Windows XP, Vista, or 7. Datum precision: Horizontal Coordinates have a Positional Uncertainty of 0.04 metres at epoch 1994.0 Ellipsoidal Heights have an uncertainty of 0.10 m Proposed Developments: Densification of PNG94 and improved tidal monitoring around PNG is underway. A readjustment of the network is also proposed during 2012 in order to reduce the uncertainities from 40 mm to 10 mm. A deformation model to enable conversion from kinematic ITRF2008 to PNG94 coordinates is also under development. Check this web-page for any developments. Technical Questions and enquiries: Contact Richard Stanaway richard.stanaway@quickclose.com.au for any technical information regarding PNG94, transformations and vertical datums.
|
Maintained by: Richard Stanaway, Quickclose Pty. Ltd.
Last Updated: 2nd December 2011